Reclamation Information Sharing Environment (RISE)

Unexpected water losses and gains on Lower Colorado River reach between Parker Dam and Imperial Dam challenge the Bureau of Reclamation’s Yuma Area Office (YAO) daily operations, which aim at delivering water to irrigation districts while minimizing excess flow. This project investigated the origin of these losses and gains and explored the potential for calibrated precipitation forecasts to predict weather-related losses and gains at lead times of 1-5 days. Predictability was found to be low due to significant unexplained variance in the loss-gain time series unrelated to weather, as well as generally limited precipitation predictability in this area. However, probabilistic forecasts were found to skillfully predict increased odds for all gains and medium-size gains. While specific to the domain of YAO, these results might be transferable to other Reclamation operations in need of short-term loss-gain forecasts.